﻿/*                       NOTICE
 * 
 * This software was produced for the U. S. Government
 * under Contract No. FA8721-10-C-0001, and is
 * subject to the Rights in Noncommercial Computer Software
 * and Noncommercial Computer Software Documentation Clause
 * (DFARS) 252.227-7014 (JUN 1995)
 * 
 * Approved for Public Release: 11-2435
 * © 2011 The MITRE Corporation. All Rights Reserved. 
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 * http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */


using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Microsoft.Xna.Framework;

namespace MXSE.MultiTouch.Gestures
{
    public class ZoomGesture : ComplexGesture
    {
        /// <summary>
        /// Requires two SlideGestures, order doesn't matter.
        /// </summary>
        /// <param name="first">One SlideGesture of the ZoomGesture.</param>
        /// <param name="second">Other SlideGesture of the ZoomGesture.</param>
        public ZoomGesture(SlideGesture first, SlideGesture second)
        {
            AddBasic(first);
            AddBasic(second);
        }

        public ZoomGesture(DragGesture first, DragGesture second)
        {
            AddBasic(first);
            AddBasic(second);
        }

        private float direction = 0;
        private float magnitude = 0;
        private float lastmagnitude = 0;

        public override void Update()
        {
            base.Update();
            DragGesture first = (DragGesture)Basics[0];
            DragGesture second = (DragGesture)Basics[1];
            double distance = Vector3.Distance(first.startPosition, second.startPosition);
            double difference1 = Vector3.Distance(first.currentPosition, second.startPosition) - distance;
            double difference2 = Vector3.Distance(second.currentPosition, first.startPosition) - distance;
            magnitude = (float)(difference1 + difference2) / 2.0f;

            if (Math.Abs(lastmagnitude - magnitude) > 0.001)
            {
                //if (magnitude < 0)
                  //  direction = 1.0f;
                //else direction = 0.0f;
                lastmagnitude = magnitude;
                contactManager.recognizer.publishMessage(
                    "Zoom " + Id + " changed magnitude to " + magnitude,
                    "ZoomChange",
                    Id,
                    0, 0, 0, 0, magnitude, direction
                );
            }
        }

        /// <summary>
        /// Overridden method.
        /// </summary>
        /// <returns>True if gesture should be removed.</returns>
        public override bool Destroyed()
        {
            return base.Destroyed();
        }

        public override void OnDeath()
        {
            //Basics[0].Parent = null;
            //Basics[1].Parent = null;
            contactManager.recognizer.publishMessage(
                "Zoom " + Id + " ended.",
                "ZoomEnd",
                Id,
                0, 0, 0, 0, 0, 0
            );
        }

        public override void Start()
        {
            BasicGesture first = Basics[0];
            BasicGesture second = Basics[1];
            first.startPosition = first.currentPosition;
            second.startPosition = second.currentPosition;
            Id = first.Id + second.Id;

            Vector3 centroid = (first.startPosition + second.startPosition) / 2;
            contactManager.recognizer.publishMessage(
                "Starting zoom " + Id + ".",
                "ZoomStart",
                Id,
                0, 0, 0, 0, centroid.X, centroid.Y
            );
        }
    }
}
